Contamination incident at Koeberg

22 September 2010

South African utility Eskom has launched an investigation into a contamination incident earlier this month at its Koeberg nuclear power plant near Cape Town in which 91 workers received small doses of radiation.

Koeberg (Image: Philipp P Egli)

Unit 1 of the two-unit Koeberg plant was shut down for a scheduled refuelling and maintenance outage on 23 August. The reactor is expected to be brought back into operation by the end of October.

However, Eskom reported that on 12 September a radiation contamination incident involving cobalt-58 had occurred at the plant. The company said that, in accordance with normal safety and health procedures, 91 workers were evaluated to monitor their levels of radiation. It was found that the entire group had radiation levels considerably below the allowable dose of 20,000 microSieverts set by South Africa's National Nuclear Regulator. The highest dose measured in the group was 500 microSieverts.

In a statement, Eskom said: "The levels of uptake detected do not pose any harmful effects to the health of people or animals. All the workers affected by the incident have already returned to work."

It added, "The Koeberg management is satisfied that all the necessary precautions were taken and all procedures and regulations were adhered to. Action was immediately taken to protect workers and to reduce contamination levels to an absolute minimum. Airborne radiation levels had returned to normal by 14 September, and workers were then allowed back into the reactor building to commence their work."

Eskom said that close monitoring of the airborne conditions inside the reactor building continues to be in place.

A technical team has been assigned by the company to review the incident and recommend steps to avoid a similar occurrence in future.

Eskom spokeswoman Karen de Villiers told the Business Report newspaper, "We had a chat with the workers because the issue was an emotional one." She added, "Frankly, they would pick up more radiation from a couple of plane trips to Johannesburg."